The third generation mobile communication standardization organization launches an SAE (System Architecture Evolution, system architecture evolution) system to enhance competitive strength of a future network. The SAE system includes network elements such as an eNodeB (enhanced NodeB, enhanced base station), an MME (Mobility Management Entity, mobility management entity), an SGW (Serving Gateway, serving gateway entity), and a PGW (Packet Network Data Gateway, packet data network gateway entity). When a UE (User Equipment, user equipment) accesses the SAE system and needs to establish a connection with a network, the MME selects an SGW and a PGW for the UE, and then the UE establishes a connection with a network through the eNodeB, and the SGW and PGW selected by the MME for the UE.
Currently, when the UE needs to establish a connection with the network, the MME acquires, according to the TAI (Tracking Arar Identity, tracking area identity) of the eNodeB selected by the UE, all SGWs capable of serving the UE, and acquires, according to an APN (Access Point Name, access point name) subscribed by the UE, a PGW capable of serving the UE; and then selects an SGW from all the acquired SGWs for the UE. Then the UE establishes a connection with the network through the eNodeB selected by the UE itself, the SGW selected by the MME, and the acquired PGW.
If a user plane path between the SGW selected by the MME for the UE and the eNodeB accessed by the UE fails, or a path between the SGW selected by the MME for the UE and the acquired PGW fails, establishment of the connection between the UE and the network fails; in this case, the MME needs to reselect an SGW for the UE to establish a connection, causing increase of time consumption of network access for the UE and a waste of a lot of network resources.